Zoltan Hudak / CANnucleo

Controller Area Network library for NUCLEO boards equipped with CAN peripheral.

Dependents:   Nucleo-Courtois CANBLE CANnucleo_Hello3 Nucleo_Serialprintf ... more

Controller Area Network library for the NUCLEO and DISCOVERY boards equipped with CAN peripheral


Information

Because CAN support has been finally implemented into the mbed library also for the ST boards there is no need to use the CANnucleo library anymore (however you may if you want). The CAN_Hello example is trying to demonstrate the mbed built-in CAN API with NUCLEO boards.


Provides CAN support for the following boards:

with the following features:

  • Easy to use. Delete the mbed library from your project and import the latest mbed-dev and CANnucleo libraries. In the mbed-dev library open the device.h file associated with the selected target board and add #undef DEVICE_CAN as follows:

device.h

#ifndef MBED_DEVICE_H
#define MBED_DEVICE_H

//=======================================
#define DEVICE_ID_LENGTH       24

#undef DEVICE_CAN

#include "objects.h"

#endif

See the CANnucleo_Hello demo for more details.

  • Automatic recovery from bus-off state can be enabled/disabled in the constructor (defaults to ENABLE).
  • Up to 14 filters (0 - 13) are available for the application to set up for message filtering performed by hardware.
    For more details see below or have a look at the comments in CANnucleo.cpp.
  • One CAN channel per NUCLEO board is supported. The CAN peripheral can be connected either to pins PA_11, PA_12 (Receiver, Transmitter) or to pins PB_8, PB_9 (Receiver, Transmitter). This is configured when creating a CAN instance.
  • Simplifies adding/getting data to/from a CAN message by using the << (append) and the >> (extract) operators.

Import programCANnucleo_Hello

Using CAN bus with NUCLEO boards (Demo for the CANnucleo library).

Last commit 28 May 2017 by Zoltan Hudak



Filtering performed by the built-in CAN controller without disturbing the CPU

CANnucleo supports only mask mode and 32-bit filter scale. Identifier list mode filtering and 16-bit filter scale are not supported. There are 14 filters available (0 - 13) for the application to set up. Each filter is a 32-bit filter defined by a filter ID and a filter mask. If no filter is set up then no CAN message is accepted! That's why filter #0 is set up in the constructor to accept all CAN messages by default. On reception of a message it is compared with filter #0. If there is a match, the message is accepted and stored. If there is no match, the incoming identifier is then compared with the next filter. If the received identifier does not match any of the identifiers configured in the filters, the message is discarded by hardware without disturbing the software.

CAN filter function - designed to setup a CAN filter

int CAN::filter(unsigned int id, unsigned int mask, CANFormat format, int handle)

Parameters

id - 'Filter ID' defines the bit values to be compared with the corresponding received bits.

Mapping of 32-bits (4-bytes) :

STID[10:3]STID[2:0] EXID[17:13]EXID[12:5]EXID[4:0] IDE RTR 0
  • STID - Stardard Identifier bits
  • EXID - Extended Identifier bits
  • [x:y]- bit range
  • IDE - Identifier Extension bit (0 -> Standard Identifier, 1 -> Extended Identifier)
  • RTR - Remote Transmission Request bit (0 -> Remote Transmission Request, 1 -> Standard message)

mask - 'Filter mask' defines which bits of the 'Filter ID' are compared with the received bits and which are disregarded.
Mapping of 32-bits (4-bytes) :

STID[10:3]STID[2:0] EXID[17:13]EXID[12:5]EXID[4:0] IDE RTR 0
  • STID - Stardard Identifier bits
  • EXID - Extended Identifier bits
  • [x:y]- bit range
  • IDE - Identifier Extension bit
  • RTR - Remote Transmission Request bit
  • 1 -> bit is considered
  • 0 -> bit is disregarded

format - This parameter must be CANAny
handle - Selects the filter. This parameter must be a number between 0 and 13.
retval - 0 - successful, 1 - error, 2 - busy, 3 - time out

Example of filter set up and filtering

Let's assume we would like to accept only messages with standard identifier 0x207:

STID[15:0] = 0x207 = 00000010 00000111


We map the STID to filter ID by shifting the bits adequately:

Filter ID = STID << (16 + (15 - 10)) = STID << 21 = 01000000 11100000 00000000 00000000


To compare only the bits representing STID we set the filter mask appropriately:

Filter mask = 11111111 11100000 00000000 00000100 = 0xFFE00004
              |||||||| |||                    |
              -------- ---                    |
                  |     |                     |
           STID[10:3]  STID[2:0]             IDE


Recall that filter #0 has been set up in the constructor to accept all CAN messages by default. So we have to reconfigure it. If we were set up filter #1 here then filter #0 would accept all the messages and no message would reach filter #1!
To reconfigure (set up) filter #0 we call:

can.filter(0x207 << 21, 0xFFE00004, CANAny, 0);



            Only these bits of 'Filter id' (set to 1 here in 'Filter mask') are compared 
            with the corresponding bits of received message (the others are disregarded)
                                |
                 ---------------------------------
                 |||||||| |||                    |
   Filter mask = 11111111 11100000 00000000 00000100 (= 0xFFE00004)
   Filter id   = 01000000 11100000 00000000 00000000 (= 0x40E00000)
                 |||||||| |||                    |
                 ---------------------------------
                                |
            To accept the message the values of these bits must match.
            Otherwise the message is passed to the next filter or
            discarded if this was the last active filter.
                                |
                 ---------------------------------
                 |||||||| |||                    |
   Received id = 01000000 11100000 00000000 00000010 (= 0x40E00002)
                             ||||| |||||||| ||||| ||
                             -----------------------
                                         |
                          These bits (set to 0 in 'Filter mask') are disregarded (masked).
                          They can have arbitrary values.


NOTE: For the meaning of individual bits see the mapping of 32-bits explained above.

We can use the filter function to setup more (up to 14) CAN filters for example as follows:

can.filter(0x207 << 21, 0xFFE00004, CANAny, 0);    // filter #0
can.filter(0x251 << 21, 0xFFE00004, CANAny, 1);    // filter #1
can.filter(0x304 << 21, 0xFFE00004, CANAny, 2);    // filter #2
...

cannucleo_api.c

Committer:
hudakz
Date:
2016-12-25
Revision:
26:321a5b290148
Parent:
25:173eea49222f
Child:
27:eed6929956ea

File content as of revision 26:321a5b290148:

/*
  ******************************************************************************
  * @file    can_api.c
  * @author  Zoltan Hudak
  * @version 
  * @date    04-August-2015
  * @brief   CAN api for NUCLEO-F103RB platform
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2015 Zoltan Hudak <hudakz@inbox.com>
  *
  * All rights reserved.

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
#include "cannucleo_api.h"
#include "can_helper.h"
#include "pinmap.h"

extern void (*rxCompleteCallback)(void);
extern CAN_HandleTypeDef _canHandle;

static uint32_t          irq_id = 0;
static can_irq_handler   irq_handler = 0;

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_init(PinName rd, PinName td, FunctionalState abom) {
    initCAN(rd, td, abom);
    can_filter(0, 0, CANAny, 0);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_free(void) {
    HAL_CAN_MspDeInit(&_canHandle);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
int can_frequency(int hz) {
    HAL_NVIC_DisableIRQ(CAN_IRQ);
    
#if defined(TARGET_NUCLEO_F072RB) || \
    defined(TARGET_NUCLEO_F091RC)
    
        // APB1 peripheral clock = 48000000Hz
        
    switch(hz) {
    case 1000000:
        // 1000kbps bit rate
        _canHandle.Init.Prescaler = 4;      // number of time quanta = 48000000/4/1000000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ;  // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
        break;
 
    case 500000:
        // 500kbps bit rate
        _canHandle.Init.Prescaler = 8;      // number of time quanta = 48000000/8/500000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ;  // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
        break;
 
    case 250000:
        // 250kbps
        _canHandle.Init.Prescaler = 12;     // number of time quanta = 48000000/12/250000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;
 
    case 125000:
        // 125kbps
        _canHandle.Init.Prescaler = 24;     // number of time quanta = 48000000/24/125000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;
 
    default:
        // 125kbps (default)
        _canHandle.Init.Prescaler = 24;     // number of time quanta = 48000000/24/125000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
    }

#elif defined(TARGET_NUCLEO_F103RB) || \
    defined(TARGET_NUCLEO_F303RE) || \
    defined(TARGET_NUCLEO_F334R8) || \
    defined(TARGET_DISCO_F334C8)
    
    // APB1 peripheral clock = 36000000Hz

    switch(hz) {
    case 1000000:
        // 1000kbps bit rate
        _canHandle.Init.Prescaler = 3;      // number of time quanta = 36000000/3/1000000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ;  // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
        break;

    case 500000:
        // 500kbps bit rate
        _canHandle.Init.Prescaler = 6;      // number of time quanta = 36000000/6/500000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ;  // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
        break;

    case 250000:
        // 250kbps
        _canHandle.Init.Prescaler = 9;      // number of time quanta = 36000000/9/250000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;

    case 125000:
        // 125kbps
        _canHandle.Init.Prescaler = 18;     // number of time quanta = 36000000/18/125000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;

    default:
        // 125kbps (default)
#if DEBUG
        printf("Unknown frequency specified!\r\n");
        printf("Using default 125kbps\r\n");
#endif
        _canHandle.Init.Prescaler = 18;     // number of time quanta = 36000000/18/125000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
    }
    
#elif defined(TARGET_NUCLEO_F303K8)
    
    // APB1 peripheral clock = 32000000Hz

    switch(hz) {
    case 1000000:
        // 1000kbps bit rate
        _canHandle.Init.Prescaler = 2;      // number of time quanta = 32000000/2/1000000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;

    case 500000:
        // 500kbps bit rate
        _canHandle.Init.Prescaler = 4;      // number of time quanta = 32000000/4/500000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;

    case 250000:
        // 250kbps
        _canHandle.Init.Prescaler = 8;      // number of time quanta = 32000000/8/250000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;

    case 125000:
        // 125kbps
        _canHandle.Init.Prescaler = 16;     // number of time quanta = 32000000/16/125000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
        break;

    default:
        // 125kbps (default)
#if DEBUG
        printf("Unknown frequency specified!\r\n");
        printf("Using default 125kbps\r\n");
#endif
        _canHandle.Init.Prescaler = 16;     // number of time quanta = 32000000/16/125000 = 16
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_11TQ; // sample point at: (1 + 11) / 16 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_4TQ;
    }

#elif defined(TARGET_NUCLEO_F446RE)
    
    // APB1 peripheral clock = 45000000Hz

    switch(hz) {
    case 1000000:
        // 1000kbps bit rate
        _canHandle.Init.Prescaler = 5;      // number of time quanta = 45000000/5/1000000 = 9
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_6TQ;  // sample point at: (1 + 6) / 9 * 100 = 77.78%
        _canHandle.Init.BS2 = CAN_BS2_2TQ;
        break;

    case 500000:
        // 500kbps bit rate
        _canHandle.Init.Prescaler = 10;      // number of time quanta = 45000000/10/500000 = 9
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_6TQ;  // sample point at: (1 + 6) / 9 * 100 = 77.78%
        _canHandle.Init.BS2 = CAN_BS2_2TQ;
        break;

    case 250000:
        // 250kbps
        _canHandle.Init.Prescaler = 15;      // number of time quanta = 45000000/15/250000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ; // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
        break;

    case 125000:
        // 125kbps
        _canHandle.Init.Prescaler = 30;     // number of time quanta = 45000000/30/125000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ; // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
        break;

    default:
        // 125kbps (default)
#if DEBUG
        printf("Unknown frequency specified!\r\n");
        printf("Using default 125kbps\r\n");
#endif
        _canHandle.Init.Prescaler = 30;     // number of time quanta = 45000000/30/125000 = 12
        _canHandle.Init.SJW = CAN_SJW_1TQ;
        _canHandle.Init.BS1 = CAN_BS1_8TQ; // sample point at: (1 + 8) / 12 * 100 = 75%
        _canHandle.Init.BS2 = CAN_BS2_3TQ;
    }
    
#endif

    HAL_CAN_Init(&_canHandle);
    HAL_NVIC_EnableIRQ(CAN_IRQ);
   
    return 1;
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_callback(void) {
    irq_handler(irq_id, IRQ_RX);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_irq_init(uint32_t id, can_irq_handler handler) {
    irq_id = id;
    irq_handler = handler;
    rxCompleteCallback = can_callback;

    if(HAL_CAN_Receive_IT(&_canHandle, CAN_FIFO0) != HAL_OK) {
#ifdef DEBUG
        printf("CAN reception initialization error\r\n");
#endif
    }
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_irq_free(void) {
    rxCompleteCallback = 0;
}   

/**
 * @brief
 * @note
 * @param
 * @retval
 */
int can_write(CAN_Message msg, int cc) {
    int i = 0;

    if(msg.format == CANStandard) {
        _canHandle.pTxMsg->StdId = msg.id;
        _canHandle.pTxMsg->ExtId = 0x00;
    }
    else {
        _canHandle.pTxMsg->StdId = 0x00;
        _canHandle.pTxMsg->ExtId = msg.id;
    }

    _canHandle.pTxMsg->RTR = msg.type == CANData ? CAN_RTR_DATA : CAN_RTR_REMOTE;
    _canHandle.pTxMsg->IDE = msg.format == CANStandard ? CAN_ID_STD : CAN_ID_EXT;
    _canHandle.pTxMsg->DLC = msg.len;

    for(i = 0; i < msg.len; i++)
        _canHandle.pTxMsg->Data[i] = msg.data[i];

    if(HAL_CAN_Transmit(&_canHandle, 10) != HAL_OK) {
#ifdef DEBUG
        printf("Transmission error\r\n");
#endif
        return 0;
    }
    else
        return 1;
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
int can_read(CAN_Message* msg, int handle) {
    int i;
    msg->id = _canHandle.pRxMsg->IDE == CAN_ID_STD ? _canHandle.pRxMsg->StdId : _canHandle.pRxMsg->ExtId;
    msg->type = _canHandle.pRxMsg->RTR == CAN_RTR_DATA ? CANData : CANRemote;
    msg->format = _canHandle.pRxMsg->IDE == CAN_ID_STD ? CANStandard : CANExtended;
    msg->len = _canHandle.pRxMsg->DLC;
    for(i = 0; i < msg->len; i++)
        msg->data[i] = _canHandle.pRxMsg->Data[i];
        
    return msg->len;
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
int can_mode(CanMode mode) {
    switch(mode) {
    case MODE_RESET:
        return HAL_ERROR;

    case MODE_NORMAL:
        _canHandle.Init.Mode = CAN_MODE_NORMAL;
        break;

    case MODE_SILENT:
        _canHandle.Init.Mode = CAN_MODE_SILENT;
        break;

    case MODE_TEST_GLOBAL:
        _canHandle.Init.Mode = CAN_MODE_LOOPBACK;
        break;

    case MODE_TEST_LOCAL:
        _canHandle.Init.Mode = CAN_MODE_LOOPBACK;
        break;

    case MODE_TEST_SILENT:
        _canHandle.Init.Mode = CAN_MODE_SILENT_LOOPBACK;
        break;
    }

    return HAL_CAN_Init(&_canHandle);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
int can_filter(uint32_t id, uint32_t mask, CANFormat format /*=CANAny*/, int32_t handle /*=0*/ ) {
    CAN_FilterConfTypeDef   sFilterConfig;

    sFilterConfig.FilterNumber = handle;    // Specifies the filter number (must be a number between 0 and 13 at 32-bit filter scale)
    sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
    sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
    sFilterConfig.FilterIdHigh = (((id) >> 16) & 0xFFFF);
    sFilterConfig.FilterIdLow = ((id) & 0xFFFF);
    sFilterConfig.FilterMaskIdHigh = (((mask) >> 16) & 0xFFFF);
    sFilterConfig.FilterMaskIdLow = ((mask) & 0xFFFF);
    sFilterConfig.FilterFIFOAssignment = 0;
    sFilterConfig.FilterActivation = ENABLE;
    sFilterConfig.BankNumber = 0;           // Selects the start bank filter
    return HAL_CAN_ConfigFilter(&_canHandle, &sFilterConfig);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_reset(void) {
    __HAL_CAN_RESET_HANDLE_STATE(&_canHandle);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
unsigned char can_rderror(void) {
    return HAL_CAN_GetError(&_canHandle);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
unsigned char can_tderror(void) {
    return HAL_CAN_GetError(&_canHandle);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void can_monitor(int silent) {

    // not implemented
}